August
16, 2007 — NOAA hydrologists indicate that Lake Superior is nearing
record lows for the month of August, a trend that if continued could
break past record lows for the months of September and October. NOAA’s
Great Lakes Environmental Research
Laboratory is able to forecast lake levels 12 months in advance
using current hydrological conditions combined with NOAA’s long-term
climate outlooks.

“Lake
Superior is less than six centimeters higher than its August record
low of 182.97 meters which was set in 1926, and it looks as though the
water levels may continue to plunge," said Cynthia
Sellinger, deputy director of NOAA's Great Lakes Environmental Research
Laboratory in Ann Arbor, Mich. "NOAA's lake level forecasts predict
that there is a 15 to 20 percent probability that new monthly records
will be set sometime this fall."

As of today, the level of Lake Superior was 183.028 meters. The record
low level for September is 183.06 meters set in 1926. That is also the
record low level for October, which was set in 1864. Records date back
to 1860.

Lake Superior, with a surface area of 31,700 square miles, is second
in area only to the Caspian Sea, and is greater than the combined areas
of Vermont, Massachusetts, Rhode Island, Connecticut, and New Hampshire.
For every inch Lake Superior drops, 529 billion gallons of water are
displaced. In the past decade, 12.7 trillion gallons of water have left
Lake Superior.

The
lake has been decreasing by a rate of 10 mm every year since 1978, and
has dropped a dramatic two feet during the last decade. The Great Lakes
region has been experiencing warmer winters since 1997, and the combination
of warmer air temperatures and less ice cover leads to increased evaporation
rates during the winter. Also, with less snow pack, there is less spring
runoff to replenish the lakes. (Click NOAA image for larger
view of Lake Superior water levels in 2007 compared to record high and
low water levels. Please credit “NOAA.”)

Observations
of precipitation, evaporation, ice cover, snow pack and other factors
are critical to support the forecast models that allow for lake level
prediction. NOAA, other federal agencies and the international community
are working to build a integrated system, the Global
Earth Observation System of Systems, to provide relevant and timely
environmental information such as this to users around the world. The
goal is to achieve societal, economic, environmental and health benefits
through an increased understanding of the Earth’s systems.

Lake Superior’s
record low of 182.69 meters was set in April 1926, the same year the
lake reached an averaged annual record low of 182.90 meters as a result
of a major climatic event that led to the dust bowl. Sellinger said
that dramatic water level changes are generally caused by major climatic
events. This includes the record high lake levels in the 1980s because
of extreme rainfall, as well as the most recent drop in lake levels
that were partially caused by the strong La
Niña event in 1998 that affected the jet stream through the
Great Lakes area and led to extreme droughts.

Anthropogenic
causes could contribute to lower water levels as well. Canals and rivers
are often dredged in the Great Lakes basin to allow large cargo ships
to pass. As rivers are dredged, the channels for water to flow out of
the Great Lakes basin are broadened, allowing for more water to run
out.

Lower
water levels mean more dredging and less cargo for the shipping industries
that rely on the Great Lakes waterway as an essential route from Africa,
Europe, and Asia to ports like Montreal, Detroit, and Duluth. On average,
for every inch of low water levels, cargo ships must reduce their load
by 50 to 270 tons, therefore providing less cargo for the same amount
of shipping time. The economic impact of reduced cargo capacity eventually
trickles down to consumers.

The estimated
Great Lakes $16 billion recreation boating industry and the $4 billion
sports fishing industry have also felt the effects of lower water levels.
With marinas either dredging, relocating, or closing down completely,
boaters are having a hard time launching boats, as well as navigating
shallow waters and trying to use docks that were built when water levels
were two feet higher.

NOAA,
an agency of the U.S. Commerce Department,
is celebrating 200 years
of science and service to the nation. From the establishment of
the Survey of the Coast in 1807 by Thomas Jefferson to the formation
of the Weather Bureau and the Commission of Fish and Fisheries in the
1870s, much of America's scientific heritage is rooted in NOAA.

NOAA is dedicated to enhancing economic security and national safety
through the prediction and research of weather and climate-related events
and information service delivery for transportation, and by providing
environmental stewardship of our nation's coastal and marine resources.
Through the emerging Global Earth Observation System of Systems (GEOSS),
NOAA is working with its federal partners, more than 70 countries and
the European Commission to develop a global monitoring network that
is as integrated as the planet it observes, predicts and protects.